The present invention is directed towards vehicular transmissions having a pair of countershafts in addition to a mainshaft such as the twin countershaft transmission described in U.S. Pat. No. 4,640,145, the disclosure of which is included herein by reference.
Such countershaft type transmissions are commonly found in track particularly heavy duty track, applications to provide both high torque and multiple gear ratio options.
Heretofore, the transmission's main drive gear which is driven by an input shaft from the vehicle's engine has characteristically exhibited rattle noise particularly when the vehicle's engine is idling and the transmission is in neutral.
The present invention in addition to limiting axial and radial movement between a transmission input shaft and main drive gear also effectively reduces noise by providing a high degree of rotary movement between splines that engage the two together.